Analytical Protocol to Estimate the Relative Importance of Environmental and Anthropogenic Factors in Influencing Runoff Quality in the Bumbu Watershed, Papua New Guinea

Abstract

The wellbeing, socio-economic viability and the associated health of the inhabitant species of any ecosystem are largely dependent on the quality of its water resources. In this regard, we developed a protocol to measure the potential impact of various environmental and anthropogenic factors on runoff quality at 22 water sampling sites across the Bumbu Watershed in Papua New Guinea. For this purpose, we utilized Digital Elevation Models and several GIS techniques for delineation of stream drainage patterns, classification of the watershed based on Land Use/Land Cover, spatial interpolation of rainfall patterns and computation of the corresponding factor runoff. Our study concludes that a variety of potential challenges to surface water quality are possible such as natural geologic and geochemical inputs, runoff accumulation of precipitation and organic matter pollutants. The developed protocol can also accommodate socio-economic factors such as community and household health, sanitation and hygiene practices, pollution and waste disposal. This research lays the foundation for further development of an all-inclusive correlational analysis between the relative importance values of the factors influencing runoff and spatially distributed water quality measurements in the Bumbu basin.

Evaluating the Impacts of Environmental and Anthropogenic Factors on Water Quality in the Bumbu River Watershed, Papua New Guinea

“…Some of the sampling stations were situated between three major bridges (Bumbu bridge, Kamkumu bridge, and Taraka bridge), and others were located near major settlements, industrial areas, and rainforest habitats. The 22 sampling points are grouped in three main series: UA, UB, UC, corresponding to samples taken from the main stream, the right side of the stream, and the left side of the stream, respectively [19]. The environmental parameters measured were alkalinity, conductivity, total dissolved solids (TDS), turbidity, water hardness, E. coli, heavy metals, temperature, and pH.…”

“…GPS coordinates were recorded using the Garmin GPSMAP 64sc (Garmin, Olathe, KS, USA) and are shown in Doaemo et al (2020b) [19]. Three water samples of 300 mL were collected near the middle of the water body at each of the 22 sampling stations.…”

“…Following the protocol developed by Doaemo et al (2020b) [19], relative importance values were computed for numerous runoff factors such as roads, streets, urbanized and semi-urbanized landscapes, rainfall patterns and mature and regenerating forested landscapes. Using line-vector analysis, stream and road networks were assembled for runoff compilation.…”

“…GIS software features enabled stream network delineation, which combined with aerial photography and satellite imagery, resulted in partitioning the watershed into five land-use classes: Dense forest, Regenerating forest, Green space, Semi-urban and Highly urban [19].…”

Geographic Location System for Identifying Urban Road Sections Sensitive to Runoff Accumulation

“…However, these tools are not open-source software, which limits their extrapolation potential. An alternative to these models can be found in the combination of a Geographic Information System (GIS) and 1D stormwater tools [8]. GIS enables creating the spatial information related to the geometry of the hydrological elements present in urban areas, whilst stormwater models use this information as inputs to simulate the processes occurring in them.…”